WO2016192975A1

WO2016192975A1 - Hermetic compressor with an improved lubrication performance

Info

Publication number: WO2016192975A1
Application number: PCT/EP2016/060987
Authority: WO
Inventors: Husnu Kerpicci; Yasam UZUN
Original assignee: Arcelik Anonim Sirketi
Priority date: 2015-06-02
Filing date: 2016-05-17
Publication date: 2016-12-08

Abstract

The present invention relates to a hermetic type compressor (1) comprising a motor (2) composed of a stator (3) and a rotor (4); a crankshaft (5) that transfers the movement received from the rotor (4); a piston-rod mechanism (6); a cylinder block (7) that bears the crankshaft (5) and the piston-rod mechanism (6); a casing (8) wherein the oil for lubrication of the movable components and the bearings (Y) is placed; a vertical channel (9) that opens into the crankshaft (5), and a oil suction apparatus (10) that is positioned in the channel (9). In particular, the invention is related to a flow guide (12) which is located in a countersink (13) at the upper end of the vertical channel (9) in order to more efficiently guide the oil flow towards the horizontal outlet hole (11). For this purpose a guiding surface (14) is foreseen.

Description

[Title established by the ISA under Rule 37.2] HERMETIC COMPRESSOR WITH AN IMPROVED LUBRICATION PERFORMANCE

The present invention relates to a hermetic compressor wherein the lubrication performance of the movable components and the bearings is improved.

In household appliances, preferably in cooling devices, the circulation of the refrigerant fluid used for refrigeration is provided by a hermetic compressor. In the compressors used in the cooling devices, the oil is delivered to the movable components and the bearings by means of an oil suction tube connected to the crankshaft transmitting the movement of the compressor motor and by means of the channels arranged on the crankshaft. Moreover, the use of oil suction apparatuses with a helical toothed structured disposed into the crankshaft so as to contribute to the oil suction thereof is known. However, at the stopping time of the compressor, the oil in the movable components at the upper side of the motor, the bearings and the crankshaft trickles towards the lower casing with the effect of gravity. This situation causes the lack of sufficient oil in the lubrication system wherein the compressor is operated again. Due to dry friction insufficient lubrication causes abrasions in the movable components and the journal or roller bearings, thus decreasing the efficiency of the compressor.

In the state of the art, a channel is opened in the crankshaft and the oil suction apparatus is inserted into the said channel. Since the channel opened in the crankshaft is obtained by means of a drill, the upper side of the channels is in form of countersink. In the state of the art design, the oil sent from the helical structure on the oil suction apparatus to the channel forms a vortex at the countersink-shaped portion before leaving the lubrication hole bored on the crankshaft. This situation delays the initial discharge moment of the oil and decreases the flow rate of the oil. Thus, the efficiency of the compressor is adversely affected and in the movable components problems such as mechanical losses and reduced life span occur.

In the state of the art European Patent No. EP0815360, an oil suction apparatus with a helically-toothed outer surface is disposed into the crankshaft. The oil suction apparatus is fixed to the stator by means of the support arms.

The aim of the present invention is the realization of a compressor, wherein lubrication of the movable components and the bearings is improved.

The compressor realized in order to attain the aim of the present invention, explicated in the first claim and the respective claims thereof comprises a crankshaft that transfers the movement received from the motor; a channel that is opened upwards from the end of the crankshaft immersed into the oil in the casing; a fixed or mobile oil suction apparatus; an outlet hole (lubrication hole) that is arranged on the crankshaft, and a flow guide that is disposed into the channel at the crankshaft between the oil suction apparatus and the upper end of the channel and that enables the oil sucked into the channel to be directly guided towards the outlet hole.

The flow guide of the present invention is disposed between the outlet hole and the upper end of the channel so as to remain in the channel at the upper side of the outlet hole. A countersink opened by means of a drill, etc. during the production is provided at the upper end of the channel and the flow guide is positioned in the countersink.

In an embodiment of the present invention, the lower surface (guiding surface) of the flow guide is concave and guides the oil flow towards the outlet hole without causing any vortex.

In another embodiment of the present invention, the flow guide has a conical shape that can be seated into the countersink without any gaps.

In another embodiment of the present invention, the flow guide is configured as an elliptic paraboloid.

In another embodiment of the present invention, the flow guide is snap-fittingly mounted to the upper end of the channel in the crankshaft.

In another embodiment of the present invention, the flow guide is fixed to the oil suction apparatus by means of a shaft.

By means of the present invention, by closing the countersink gap at the upper side of the channel opened in the crankshaft for lubrication, vortices occurring during the delivery of the oil are prevented and the oil is enabled to reach the outlet hole (lubrication hole) at the crankshaft more quickly. The duration that elapses for the suction and delivery of the oil from the base of the casing to the bearings is shortened and thus, the time that the bearings operated without oil at the initial start-up of the compressor, thus the risk of abrasion is reduced.

The model embodiments relating to the compressor realized in order to attain the aim of the present invention are illustrated in the attached figures, where:

Figure 1 – is the cross-sectional view of the compressor of the present invention.

Figure 2 – is the exploded view of the crankshaft, the oil suction apparatus and the guide.

Figure 3 – is the schematic view of the guide mounted to the crankshaft in an embodiment of the present invention;

Figure 4 – is the perspective view of the guide mounted to the oil suction apparatus in another embodiment of the present invention.

Figure 5 – is the front view of the guide mounted to the oil suction apparatus.

Figure 6 – is the schematic view of the guide mounted to the oil suction apparatus in the embodiment in Figure 4 and 5.

The elements illustrated in the figures are numbered as follows:

Compressor
Motor
Stator
Rotor
Crankshaft
Piston – rod mechanism
Cylinder block
Casing
Channel
Oil suction apparatus
Outlet hole
Flow guide
Countersink
Guiding surface
Shaft

Y: Bearing

K: Crankshaft oil transportation path

P: Oil suction apparatus fixing member

The hermetic type compressor (1) comprises a motor (2) composed of a stator (3) and a rotor (4); a crankshaft (5) that transfers the movement received from the rotor (4); a piston-rod mechanism (6); a cylinder block (7) that bears the crankshaft (5) and the piston-rod mechanism (6); a casing (8) wherein the oil for lubrication of the movable components like the motor (2), the crankshaft (5), the piston-rod mechanism (6) and the bearings (Y) is placed; a vertical channel (9) that opens from the lower end of the crankshaft (5) that is immersed into the oil in the casing (8) into the crankshaft (5) in the axial direction; a cylindrical oil suction apparatus (10), the outer periphery of which is in helically geared structure, that is positioned in the channel (9) one inside the other and concentrically with respect to the crankshaft (5), and that extends from the lower end of the crankshaft (5) into the channel (9), and an outlet hole (11) that is opened between the channel (9) side wall and the crankshaft (5) outer surface and that enables the oil sucked into the channel (10) by means of the oil suction apparatus (10) to be delivered to the movable components at the upper side of the crankshaft (5).

The compressor (1) of the present invention comprises a flow guide (12) that is disposed into the channel (9) so as to remain between the oil suction apparatus (10) and the upper end of the channel (9) and that enables the oil sucked into the channel (9) to be guided towards the outlet hole (11).

In an embodiment of the present invention, the flow guide (12) is disposed between the outlet hole (11) and the upper end of the channel (9) so as to remain in the channel (9) at the upper side of the outlet hole (11). The flow guide (12) extends from the upper side of the outlet hole (11) into the channel (9) in a direction perpendicular to the oil flow so as to close the upper end of the channel (9) and the oil is guided towards the outlet hole (11) without entering the upper end of the channel (9).

In another embodiment of the present invention, the compressor (1) comprises a countersink (13) that is disposed at the upper end of the channel (9) and that is formed by means of a cutting tool such as a drill bit, etc. while the channel (9) is opened in the crankshaft (5) by machining during production and the flow guide (12) that is disposed into the countersink (13).

In the compressor (1), the lower end of the crankshaft (5) is immersed into the oil in the casing (8) and the oil in the casing (8) is sucked into the crankshaft (5) by the effect of the centrifugal force. The oil is transported upwards into the channel (9) in the crankshaft (5) by means of the helically-toothed structure on the oil sucking member (10) concentrically disposed into the crankshaft (5), from the channel (9) to the preferably helical oil transportation path (K) located at the circumference of the crankshaft (5) by means of the outlet hole (9) and then to the movable components and the bearings (Y) on the motor (2). The oil moving towards the channel (9) by means of the oil suction apparatus (10) directly - without losing its speed - reaches the outlet hole (11) without any formation of vortices by means of the flow guide (12) disposed at the countersink at the upper end of the channel (9) and is then delivered to the movable components and the bearings (Y). Thus, the duration that elapses for the suction and delivery of the oil from the base of the casing (8) to the bearings (Y) is shortened when the compressors (1) starts operating and thus, the time that the bearings (Y) operated without oil at the initial start-up of the compressor (1), thus the risk of abrasion is minimized.

In an embodiment of the present invention, the flow guide (12) comprises a concave guiding surface (14) that is arranged at the lower side thereof and that meets the oil flow moving upwards through the channel (9). The concave guiding surface (14) minimizes the vortices in the flow of the oil moving towards the outlet hole (11) and enables the oil to be guided towards the outlet hole (11) in a quick and effective manner.

In an embodiment of the present invention, the flow guide (12) has a conical shape that matches the shape of the countersink (13) and that can be seated into the countersink (13) without any gaps. The flow guide (12) completely closes the countersink (13) and prevents the formation of vortices that adversely affect the oil flow.

In another embodiment of the present invention, the flow guide (12) is configured as an elliptic paraboloid. The flow guide (12) has a convex upper surface matching the concave lower guiding surface (14), providing ease of production. In this embodiment, the flow guide (12) can be produced, for example by being cut from a sheet metal and shaped in a pressing machine.

In another embodiment of the present invention, the flow guide (12) is snap-fittingly mounted to the upper end of the channel (9) in the crankshaft (5). In this embodiment, the guide (12) rotates together with the crankshaft (5) (Figure 1, Figure 2, Figure 3).

In an embodiment of the present invention, the flow guide (12) is fixed to the oil suction apparatus (10). In this embodiment, the compressor (1) comprises a fixing shaft (15) that enables the flow guide (12) to be fixed to the upper side of the oil suction apparatus (10), with one end connected to the flow guide (12) and the other end to the oil suction apparatus (10). When the oil suction apparatus (10) is placed into the channel (9) in the crankshaft (5), the flow guide (12) is positioned at the upper end of the channel (9) with gaps. In this embodiment, while the crankshaft (5) rotates, the flow guide (12) remains immobile together with the oil suction apparatus (10) or in embodiments wherein the oil suction apparatus (10) rotates, the flow guide (12) rotates together with the oil suction apparatus (10) (Figure 4, Figure 5 and Figure 6).

In the compressor (1) of the present invention, the oil suction apparatus (10) is fixed to the stator (3) by means of fixing members such as bracket, wire, etc. and remains stationary in the crankshaft (5) during the operation of the motor (2).

By means of the present invention, especially in inverter compressors (1) that can operate at variable speeds, the amount oil supplied for lubrication of the movable components and the bearings (Y) is increased at low speeds and during the initial start-up. The time required for sucking the oil from the casing (8) and delivering to the bearings (Y) decreases and a sufficient amount of oil can be delivered to the bearings (Y) during this time. The risk of operating without oil or insufficient lubrication that may occur in case the compressor (1) is operated at low speeds is minimized.

Claims

A compressor (1) comprising a motor (2) composed of a stator (3) and a rotor (4); a crankshaft (5) that transfers the movement received from the rotor (4); a piston-rod mechanism (6); a cylinder block (7) that bears the crankshaft (5) and the piston-rod mechanism (6); a casing (8) wherein the oil for lubrication of the movable components and the bearings (Y) is placed; a vertical channel (9) that opens into the crankshaft (5) in the axial direction; a cylindrical oil suction apparatus (10), the outer periphery of which is in helically geared structure, and an outlet hole (11) that opens between the channel (9) side wall and the crankshaft (5) outer surface, characterized in that a flow guide (12) that is disposed into the channel (9) between the oil suction apparatus (10) and the upper end of the channel (9) and that enables the oil sucked into the channel (9) to be guided towards the outlet hole (11).
A compressor (1) as in Claim 1, characterized in that the flow guide (12) that is disposed between the outlet hole (11) and the upper end of the channel (9) so as to remain at the upper side of the outlet hole (11).
A compressor (1) as in Claim 1, characterized in that a countersink (13) that is arranged at the upper end of the channel (9) and the flow guide (12) disposed into the countersink (13).
A compressor (1) as in any one of the Claims 1 to 3, characterized in that the flow guide (12) comprising a concave guiding surface (14) that meets the flow of the oil moving upwards through the channel (9).
A compressor (1) as in any one of the Claims 1 to 3, characterized in that the conical flow guide (12) that is seated into the countersink (13) without any gaps.
A compressor (1) as in any one of the Claims 1 to 3, characterized in that the elliptic paraboloid flow guide (12)
A compressor (1) as in any one of the Claims 1 to 3, characterized in that the flow guide (12) that is snap-fittingly mounted to the upper end of the channel (9) in the crankshaft (5).
A compressor (1) as in any one of the Claims 1 to 3, characterized in that the flow guide (12) that is fixed to the oil suction apparatus (10).
A compressor (1) as in Claim 8, characterized in that a fixing shaft (15) that enables the flow guide (12) to be fixed to the oil suction apparatus (10), with one end connected to the flow guide (12) and the other end to the oil suction apparatus (10).
A compressor (1) as in any one of the Claims 1 to 3, characterized in that the oil suction apparatus (10) that is fixed to the stator (3) or to the casing (8) and that remains stationary in the crankshaft (5) during the operation of the motor (2)